Lucie Lebeau

This paper formalizes a Nash bargaining game between two players constrained by capacity decisions made prior to entering the negotiation. In equilibrium, strategic interactions drive capacity choices to zero and shut trade down despite the existence of gains from trade. The game is embedded in a general equilibrium model of decentralized asset trade with credit frictions to investigate the interaction between availability of credit and investors’ participation, modeled through their choices of inventory and payment capacity. A partial access to credit is sufficient to restore trade. The strategic interactions between payment capacity and inventory generate endogenous heterogeneity in holdings, trade sizes and prices, and complementarity between money and credit.

We introduce a new approach to bargaining, with strategic and axiomatic foundations, into models of decentralized asset markets. According to this approach, which encompasses the Nash (1950) solution as a special case, bilateral negotiations follow an agenda that partitions assets into bundles to be sold sequentially. We construct two alternating-offer games consistent with this approach and characterize their subgame perfect equilibria. We show the revenue of the asset owner is maximized when assets are sold one infinitesimal unit at a time. In a general equilibrium model with endogenous asset holdings, gradual bargaining reduces asset misallocation and prevents market breakdowns.

In coca-growing villages of Colombia, where pesos are scarce, coca-base is not only used as the main input for cocaine production—it also acts as a complementary currency (CC), circulating locally as a medium of exchange for day-to-day transactions. This paper provides a clear rationale for the economically-motivated adoption of a CC in a small open economy underprovided with official currency. Equilibrium currency shortages arise endogenously in our model, whereby shocks to the local supply of currency have a real impact on local trade and welfare. We show how a CC can mitigate the underprovision of liquidity and derive general insights relating the CC’s characteristics to its ability to supplement the official currency. Additionally, we quantify the unintended consequences of various anti-narcotic policies pursued by the Colombian government on liquidity provision in coca-growing villages and identify the least-harmful policy tools given the policy objectives at stake.

We report on an experiment in which buyers and sellers engage in semi-structured bargaining along two dimensions: how much of a good the seller will produce and how much money the buyer will offer in exchange. Our aim is to evaluate the empirical relevance of two axiomatic bargaining solutions, the generalized Nash bargaining solution and Kalai’s proportional bargaining solution. These bargaining solutions predict different outcomes when buyers are constrained in their money holdings. We find strong evidence in support of the Kalai proportional solution and against the generalized Nash solution when buyers face liquidity constraints. Our findings have policy implications, e.g., for the welfare cost of inflation in search-theoretic models of money.

An OLG model where currency choices are endogenously driven by income heterogeneity is developed to analyze the simultaneous impact of a Central Bank Digital Currency (CBDC) on financial inclusion and bank funding. Pre-CBDC, wealthier agents use deposits while poorer agents use cash, remaining unbanked. CBDCs with higher fixed costs and interest rates are adopted by deposit holders and increase inclusion by raising deposit rates. CBDCs with lower fixed costs and interest rates are adopted by cash holders, directly increasing inclusion and inducing more favorable inclusion-intermediation trade-offs. A US calibration allows us to quantify these trade-offs conditional on CBDC design.

An increasing share of corporate loans, a critical source of firm credit, are sold off banks’ balance sheets and actively traded in a secondary over-the-counter market. We develop a microfounded equilibrium search-theoretic model with labor, credit, and financial markets to explore how this secondary loan market affects the real economy, highlighting a trade-off: while the market reduces the steady-state level of unemployment by 0.6pp, it amplifies its response to a 1% productivity drop from 3.6% to 4.3%. Secondary market frictions matter significantly: eliminating them would not only reduce unemployment by 1.2pp, but also dampen its volatility down to 2.7%.

We study the dynamic interplay between monetary policy and market power in a decentralized monetary economy. Building on Choi and Rocheteau (2024), our key innovation is to model rent seeking as a process that takes time, allowing market power to evolve gradually. Our model predicts that a gradual reduction in the nominal interest rate causes a simultaneous increase in rent-seeking effort and producers’ market power, consistent with the stylized correlation observed in the US over the last few decades. Producer entry can however reverse this relation in the short run, and neutralize it in the long run. Indeterminacy and hysteresis emerge when consumers benefit from valuable outside options, with short-run monetary policy shocks potentially locking the economy into high- or low-market-power equilibria in the long run.

This paper endogenizes the spread of an infectious disease in a random matching model with pairwise meetings, where economic and social gains arise explicitly from person-to-person contacts. When agents can decide whether to engage in interactions, complementarities in the participation decisions of individuals susceptible to contracting the disease generate a large multiplicity of equilibria through adverse selection. The lower the participation of susceptible agents, the higher the prevalence of infection in the pool of participants, further discouraging the participation of susceptible agents. I document a variety of infection dynamics, including plateaus and multiple waves. Adverse selection leads to too much isolation from susceptible agents, and in the calibrated version of the model, the cost of forgone interactions offsets the welfare gains of flattening the curve and mitigating the human toll. When agents cannot opt out of the market but can instead choose whether to wear a mask, the equilibrium is unique. In the calibrated model the human toll is lower than when considering the participation margin, yet at a significantly smaller cost.